Let it sit and don't worry. Remember that bubbling in the airlock is not an indication of fermentation, it is only an indication that CO2 is being forced out of the airlock. For a Wee Heavy I would leave it in primary for at least 3 weeks before even bothering to take a reading, but that's just me.

What made you think that you had a problem? 4 days is a perfectly normal time for me to see active fermentation stop, and you've already read 66% apparent attenuation. Depending on the yeast, that might be all you can expect from it. In reality the gravity might keep falling.